Zenit St Petersburg have denied allegations that a Russian criminal gang paid out bribes to the club's Uefa Cup opponents last season. Spanish newspapers El Pais and ABC reported that a leading Spanish judge had heard a taped telephone conversation in which Russian criminal Gennadios Petrov claimed to have paid Zenit's semi-final opponents Bayern Munich vast sums of money. Zenit are considering legal action against the papers, while Uefa say they will be investigating the claims.

"The quality of play shown by FC Zenit in the games against Rangers FC and Bayern Munich is the best proof that the victories were earned by Zenit in honest and non-compromising challenges," read a statement on Zenit's official website.

"Allegations of deals mentioned in the media are offensive to all parties mentioned. At this moment FC Zenit's legal department are evaluating the origins of the story. After this, a decision about legal means to protect the club's reputation and sport as a whole, shall be decided."

The Zenit manager Dick Advocaat denounced the allegations as lies. "This is incredible," he told the Daily Record. "All I can say is let them play the tapes so we can hear what has been said. Then everyone will know what a big lie it is.

"Everyone knows the simple truth - we had a better team than Rangers. That's why we won the Uefa Cup. Rangers played very well, but we were the better side. There was no mystery. I don't know why anybody would say something like this."

Bayern have also denied all knowledge of the allegations. "Bayern Munich knows nothing about this suspicion, and neither does the Munich prosecutor's office," said a club statement.

El Pais said an investigation against the Russian mafia led by judge Baltasar Garzon had uncovered evidence the second leg might have been fixed. The Russian champions Zenit crushed Bayern 4-0 at home in the second leg to win 5-1 on aggregate before going on to beat Rangers in the final.

"When there are rumours of this type, our members of the disciplinary committee handle them and we are going to look at this closely," the Uefa spokesman William Gaillard said.